Thanks for your info.I used your method and the number is 4 inches back from wing leading edge at the side of fuse.This seems more right. World models P51 calls for 5.5 inches and Great Plains calls for 5 3/8 inches. The 4 inch mark will be used and the control settings will be used from the other manufactures.
This plane came from someones back shelf and with no info I had to start somewhere. The 2 inch advice came as a suggestion to keep out the tail heavy as a start.These older ARF planes were not designed as todays are.Maybe that is why they are not here now.
This is not a major project now but I will post when flight is tried again.Thanks for all the input.